The present invention relates to plasma processing chambers with confinement rings
U.S. Pat. No. 6,019,060, entitled “Cam-Based Arrangement For Positioning Confinement Rings In A Plasma Processing Chamber,” by Eric H. Lenz, issued Feb. 1, 2000 discloses a plasma processing etch chamber that uses confinement rings to confine plasma within volume. The confinement rings are place within the plasma chamber walls and may help to reduce the amount of plasma and other gases reaching the chamber wall, maintain pressure within the confinement rings, and control the flow of gas past the confinement rings.
During various plasma processes, it may be desirable to increase the flow of gas past the confinement ring, while minimizing the amount of plasma and other gases reaching the chamber walls.